NAKAKITA Eiichi Kyoto University, Faculty of Engineering, Department of Global Environment Engineering, Associate Professor, 大学院・工学研究科, 助教授 (70183506)
NAKAGAWA Hajime Kyoto University, Research Center for Disaster Environment, Disaster Prevention Research Institute, Professor, 防災研究所, 教授 (80144393)
MIZUYAMA Takahisa Kyoto University, Faculty of Agriculture, Division of Forest Science, Professor, 大学院・農学研究科, 教授 (00229717)
ITOH Takahiro Ritsumeikan University, Faculty of Science and Engineering, Assistant Professor, 理工学部, 講師 (80334035)
SHIMIZU Yoshihiko Gunma University, Faculty of Engineering, Department of Civil Engineering, Associate Professor, 工学部, 助教授 (70178995)
This joint research was conducted to analyze 1999-sediment disaster from a viewpoint sediment dynamics as well as to propose reliable tools for countermeasures against sediment hazards, and four sub-topics were studied. 1. Characteristics of heavy rainfall in Caribbean Sea coastal region of north Venezuela. 2. Simulation of 1999-sediment runoffs and sediment runoff characteristics after the disaster. 3. Historical aspects of sediment disasters and 4. Countermeasures of sediment hazards. The results are summarized as follows.
1. Meteorological interactions between temporal and spatial scales associated with the heavy rainfall are analyzed. Based on the results, a method is proposed to distinguish an abnormal rainfall from numerous events.
2. 1-D and 2-D mathematical methods for predicting sediment runoff are refined by applying them to 1999-disasters and tested using sediment runoff data which have been collected since the disaster. These are assured to be powerful tools in delineating hazard maps.
3. The results obtained from the study on historical aspects of sediment disaster suggest that usual education performances, hazard maps and associated land uses are of importance to reduce sediment hazards in addition to proper structural countermeasures.
4. Mathematical tools are proposed to specify the location, type and size of debris control structure.